• 제목/요약/키워드: HTU

검색결과 6건 처리시간 0.018초

Effect of different concentrations of hypotaurine on melanosis and quality of Pacific white shrimp (Penaeus vannamei) during refrigeration

  • Zhou, Jiaying;Ying, Yubin;Zhou, Yaqi;Li, Gaoshang;Hu, Yaqin
    • Fisheries and Aquatic Sciences
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    • 제25권4호
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    • pp.231-242
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    • 2022
  • Effect of different concentrations of hypotaurine (HTU) on melanosis and quality of shrimps during 10 d storage in ice were studied. During refrigeration, the total plate count and total volatile basic nitrogen of shrimps treated with 20 g/L HTU were the lowest, and the hardness and microstructure were the best. Moreover, the score of melanoses, pH and total bile acid of shrimps treated with 20 g/L HTU were also low. Sensory evaluation showed that HTU treatment could make the shelf life of shrimps 3-4 days longer compared with the control. Based on the above physical and chemical indexes, 20 g/L HTU showed great potential as a safe inhibitor in the treatment of shrimps' melanosis.

액상 균일질 촉매를 이용한 $SO_2/NO$ 동시 처리 기술 개발 (Simultaneous Removal of $SO_2/NO$ using liquid Homogeneous Catalyst)

  • 정승호;배진열;박돈희;정경훈;차진명
    • 대한환경공학회지
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    • 제29권1호
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    • pp.62-67
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    • 2007
  • 본 연구의 목적은 액상 균일질 촉매를 이용하여 연소가스 중에 포함되어 있는 $SO_2/NO$의 동시제거 기술 개발에 있다. 연구는 bench scale/소규모 pilot scale에서 이루어졌으며 연구 결과는 다음과 같다. 1) $SO_2$는 실험조건에 상관없이 높은 제거효율을 가지는 것으로 확인되었다. 그러나 NO의 경우 충진층 높이가 증가할수록, 농도가 낮을수록, 촉매 분사량이 증가할수록 제거효율이 증가하는 것으로 나타났다. 2) Fe(II)-EDTA를 이용한 $SO_2/NO$ 동시처리 기술 개발을 위한 최적의 설계 인자는 충진 높이 =0.5 m, 액체-기체비 = 20 $L/m^3$, 반응기 단수=3단, 반응기 단면적 = 0.025 $m^2$로 결정하였다. 3) 연구 결과를 기초로 $SO_2/NO$의 동시처리 효율을 실험한 결과 각각 95%, 81% 이상 제거가 가능했다. 4) 높은 HTU는 NO의 제거에 있어 유리하지만 과도한 HTU는 스크러버의 운전효율을 감소시키므로 최적의 HTU를 결정하는 것이 필요하다.

대기질 - 강우산성도 관계식의 개발 (Development of Relationship between Air Quality and Rain Acidity)

  • 구자공;유동준
    • 한국대기환경학회지
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    • 제2권3호
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    • pp.45-51
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    • 1986
  • The simple and precise model for the estimation of rain acidity from the ambient air quality was developed using the theory of wet scrubber and the chemical equilibria of $SO_2, CO_2, and H_2O$ system. From the measured mixing height, and from the developed relationship between NTU (=number of transfer units) and the concentration of $SO_2$(aq) in rain drops, the HTU (= height equivalent to one transfer unit, i.e. mass transfer resistance) was estimated, and validated with the field-measured data. In Seoul, Korea where the effect of $SO_2$ on rainfall acidity is as high as 84% and the average mixing height is 1 km, the average HTU of $SO_2$ system was found to be 191.5m. The important parameters affecting HTU were identified as rainfall intensity and initial ambient concentration of $SO_2$, and their effects on the value of overall volumetric mass transfer coefficient were quantified.

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Ralu-Pack 250YC를 충전한 충전탑에서 암모니아가스 제거에 관한 연구 (A study on Removal of $NH_3$ Gas in a Towar using a Ralu-Pack 250YC as a Packing Material)

  • 김석택
    • 한국환경과학회지
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    • 제9권5호
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    • pp.389-392
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    • 2000
  • In this study a packed tower was selected for the treatment apparatus of $NH_3$ gas produced in industry. Formerly latticework packing has been used in preventive facility of treatment of $NH_3$ gas. However recently metallic Ralu-Pack 250YC. structured packing is usually being used in petrochemical production plant. This study is for the application the packing to the $NH_3$ gas treatment in wet scrubbing process. In Air/water system hydraulic pressure drop dependent of specific liquid load and gas capacity factor was continuous and parallel from graph. The tower height can be determuined by the number of transfer unit and the height of transfer unit influenced on liquid distribution.

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충전탑에서 흡수에 따른 물질전달과 수력학적 거동에 관한 연구 (A Study on Hydraulic Behavior and Mass Transfer by Absorption in Packing Tower)

  • 김석택
    • 한국환경과학회지
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    • 제9권5호
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    • pp.393-396
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    • 2000
  • Packing tower has been used in the chemical industry and the protection of environment for a long time. In the view of environmental protection purification of exhaust gas can be performance effective by gas absorption in counter-current packing tower. In this study characteristics of hydraulic and mass transfer were investigated in D. $0.3m {\times} H. 1.4m$ packing tower with 50mn plastic Hiflow-ring. This study was carried out "Test systems were experimented in conditions of Air, $Air/H_2O. NH_3-Air/H_2O, NH_3-Air/H_2O-H_2SO_4$ and $SO_2-Air/H_2O-NaOH$ under steady state" The extent of test included dry and wetting pressure drop physical law separation efficiency and hold-up as function of gas and liquid load.quid load.

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역류식 충전탑에서 이산화탄소 탈착과 수력학절 거동에 관한 연구 (A Study on Hydraulic Behavior and Desorption of $CO_2$ Gas in the Counter-current Packing Tower)

  • 김석택
    • 환경위생공학
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    • 제15권3호
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    • pp.94-100
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    • 2000
  • This study was carried out to interpret hydraulic behavior and CO2 gas desorption in counter-current packing tower which packed 50mm plastic Hiflow-ring. The results are as follow : To compare with conventional packing, 50mm Hiflow-ring could save energy because of low pressure drop under high load. As relative error between calculated value and investigated value was less than 6% in the loading point and flooding point we found that we are predict results mathematically which occur in packing tower. The unique magnitude of packing which was used are as follows. $C_L=2.1{\times}10^{-4}$, n=0.787 so we can predict efficiency which occur

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